The present disclosure relates generally to offset installation systems. More specifically, in certain embodiments, the present disclosure relates to offset installation systems capable of transporting equipment to a seabed without direct overhead surface equipment and associated methods.
During the lifetime of a subsea well, it may be desirable to transport subsea equipment from the surface to the sea floor. This is often accomplished using a vessel to directly lower a payload to the sea floor. In such a system, a subsea payload would typically be suspended by a cable that extends vertically from the vessel to the payload. At surface, the cable may be connected to a crane or winch on the vessel. The x-y position of the payload may be adjusted by moving the x-y position of the vessel or the crane. The z position of the payload may be controlled by raising or lowering the cable with the crane or winch. This operation may be augmented by heave compensation devices which reduce the effect of wave activity at the surface.
It may be desirable to place equipment on, or nearby, a wellbore which has experienced an uncontrolled release of hydrocarbons into the environment. Typically, the equipment would be deployed from the surface vessel vertically above the wellhead. However, this is not always possible due to the presence of flammable gas and/or volatile organic compounds rising from the well at that location. Thus, conventional methods of transporting subsea equipment to a seafloor near a wellbore experiencing an uncontrolled release of hydrocarbons may be insufficient.
It is desirable to develop a method of transporting subsea equipment to a seabed location without requiring the use of surface equipment directly above the seabed location.